.w{
    width: 12rem;
    margin: 0 auto;
}
.fl{
    float: left;
}
.fr{
    float: right;
}
*{
    padding: 0;
    margin: 0;
}
li{
    list-style: none;
}
a{
    text-decoration: none;
}
button{
    cursor: pointer;
    outline: none;
    border: none;
}
input{
    outline: none;
}
i{
    font-style: normal;
}